The present invention relates as indicated to a split locking ring for a piston cylinder actuator in general and to a locking ring having at least one axially extending surface initially lapped in its unlocked configuration accurately to conform the same in operation to the piston or cylinder surface in sliding contact therewith during relative movement therebetween in the unlocked position of the lock ring.
To replace the conventional balls, keys and fingers previously employed as locking mechanisms for locking actuators, split locking rings have recently been adopted selectively radially to expand and contract for locking and unlocking functions in a piston cylinder actuator commonly used on or in association with aircraft landing gear and the like. An example of such a split locking ring used in such environment may be found in Hallesy et at U.S. Pat. No. 3,813,065.
In such patent, the inner diametrical surface of the split locking ring is provided with a plurality of flex notches to permit flexibility for the radial movement required and to reduce the loads necessary to attain the radial expansion and contraction for the locking and unlocking functions. However, such flex notches reduce the effective bearing area for the inner diameter of the split locking ring and are also expensive to machine.
To overcome such loss of bearing area and expense, the present invention is directed to making a split ring locking assembly that does not require inner diameter flex notches to perform the radial movements required for locking and unlocking. This movement is accomplished by selecting a split locking ring having a sufficient diameter as compared to its cross-sectional configuration to provide adequate flexibility to undergo the radial movements required.
In this regard, it is a principal object of the present invention to provide such a split locking ring having an accurately lapped outer diametrical surface to conform to the inner diameter of the cylinder in the unlocked position of the ring, whereby relative axial movement therebetween occurs with substantially uniform peripheral contact therebetween. Alternatively, if the locking and unlocking functions are obtained by oppositely directed radial movements of the ring, the inner diametrical surface of the ring can be initially lapped in its radially expanded condition thereby to conform in operation to the outer diameter of the piston in sliding contact therewith during the unlocked mode of the actuator. This outer and/or inner diameter lapping procedure in the unlocked configuration for the locking ring before assembly eliminates the detected uneven wear patterns associated with conventional split locking rings and further avoids the necessity of the inner diameter flex notches to provide the necessary flexibility to approximate conformance.
It is still another object of the present invention to avoid loading eccentricities on the split lock ring during manufacture and to provide symmetry of balance and load carrying capacity. To accomplish this function, the ends of the split locking ring are radially relieved on both the inner and outer diametrical surfaces for uniform distribution of bending loads, with a flat being provided diametrically opposed therefrom on the outer diameter to provide symmetry of balance and loading.
Other objects and advantages of the present invention will become apparent as the following description proceeds.
To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.